The necessity for playground equipment in urban areas is increasing. In particular, playground equipment is being increasingly used in conjunction with rest stops, fast food establishments parks and urban schools. In these settings, heavy use precludes the placement of sand, woodchips or similar materials to soften the blow of a falling child. The use of such materials also often ends up with the area turning into a mudhole or becomes an area for harboring insects or dangerous debris such as glass. Thus, the playground equipment is generally placed atop concrete, asphalt or other hard surfaces for reduced maintenance and better sanitation.
To reduce serious injury, a shock absorbing material is installed over the asphalt or concrete subbase to attenuate the impact caused by falls from the overhead playground apparatus.
Impact absorbing mats have been described in previous inventions. In U.S. Pat. No. 3,636,577 compressible coverings for athletic uses are disclosed. The invention is particularly directed to a fastener to form a laminate sheet of the matting material. The invention is particularly adapted to gymnastic indoor and fair weather applications.
In U.S. Pat. No. 3,251,076 by D. M. Burke impact absorbing mat is set forth which utilizes air cells formed within the mat to give the mat its shock absorbing capacity. The air cells are formed such that the entire cell is defined within the confines of the outer walls of the mat. Further, the Burke patent contemplates the varying configurations for air cells formed within the mat.